/Engine/Source/Runtime/Experimental/Chaos/Public/Chaos/DenseMatrix.h
Set the 3x3 block starting at ("RowOffset", "ColumnOffset") from the specified 3x3 matrix "V" (note: assumes the input UE matrix is column-major order)
void SetBlockAt ( const int32 RowOffset, const int32 ColumnOffset, const [FMatrix33](API\Runtime\ChaosCore\Chaos\FMatrix33) & V )